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32 * $FreeBSD: src/sys/posix4/ksched.c,v 1.7.2.1 2000/05/16 06:58:13 dillon Exp $
33 * $DragonFly: src/sys/kern/kern_sched.c,v 1.4 2004/03/30 19:14:18 dillon Exp $
36 /* ksched: Soft real time scheduling based on "rtprio".
39 #include <sys/param.h>
40 #include <sys/systm.h>
42 #include <sys/kernel.h>
43 #include <sys/resource.h>
44 #include <machine/cpu.h> /* For need_user_resched */
45 #include <machine/ipl.h> /* For need_user_resched */
49 /* ksched: Real-time extension to support POSIX priority scheduling.
53 struct timespec rr_interval;
56 int ksched_attach(struct ksched **p)
58 struct ksched *ksched= p31b_malloc(sizeof(*ksched));
60 ksched->rr_interval.tv_sec = 0;
61 ksched->rr_interval.tv_nsec = 1000000000L / roundrobin_interval();
67 int ksched_detach(struct ksched *p)
75 * XXX About priorities
77 * POSIX 1003.1b requires that numerically higher priorities be of
78 * higher priority. It also permits sched_setparam to be
79 * implementation defined for SCHED_OTHER. I don't like
80 * the notion of inverted priorites for normal processes when
81 * you can use "setpriority" for that.
83 * I'm rejecting sched_setparam for SCHED_OTHER with EINVAL.
86 /* Macros to convert between the unix (lower numerically is higher priority)
87 * and POSIX 1003.1b (higher numerically is higher priority)
90 #define p4prio_to_rtpprio(P) (RTP_PRIO_MAX - (P))
91 #define rtpprio_to_p4prio(P) (RTP_PRIO_MAX - (P))
93 /* These improve readability a bit for me:
95 #define P1B_PRIO_MIN rtpprio_to_p4prio(RTP_PRIO_MAX)
96 #define P1B_PRIO_MAX rtpprio_to_p4prio(RTP_PRIO_MIN)
99 getscheduler(register_t *ret, struct ksched *ksched, struct proc *p)
103 switch (p->p_rtprio.type)
109 case RTP_PRIO_REALTIME:
121 int ksched_setparam(register_t *ret, struct ksched *ksched,
122 struct proc *p, const struct sched_param *param)
127 e = getscheduler(&policy, ksched, p);
131 if (policy == SCHED_OTHER)
134 e = ksched_setscheduler(ret, ksched, p, policy, param);
140 int ksched_getparam(register_t *ret, struct ksched *ksched,
141 struct proc *p, struct sched_param *param)
143 if (RTP_PRIO_IS_REALTIME(p->p_rtprio.type))
144 param->sched_priority = rtpprio_to_p4prio(p->p_rtprio.prio);
150 * XXX The priority and scheduler modifications should
151 * be moved into published interfaces in kern/kern_sync.
153 * The permissions to modify process p were checked in "p31b_proc()".
156 int ksched_setscheduler(register_t *ret, struct ksched *ksched,
157 struct proc *p, int policy, const struct sched_param *param)
167 if (param->sched_priority >= P1B_PRIO_MIN &&
168 param->sched_priority <= P1B_PRIO_MAX)
170 rtp.prio = p4prio_to_rtpprio(param->sched_priority);
171 rtp.type = (policy == SCHED_FIFO)
172 ? RTP_PRIO_FIFO : RTP_PRIO_REALTIME;
185 rtp.type = RTP_PRIO_NORMAL;
186 rtp.prio = p4prio_to_rtpprio(param->sched_priority);
189 /* XXX Simply revert to whatever we had for last
190 * normal scheduler priorities.
191 * This puts a requirement
192 * on the scheduling code: You must leave the
193 * scheduling info alone.
203 int ksched_getscheduler(register_t *ret, struct ksched *ksched, struct proc *p)
205 return getscheduler(ret, ksched, p);
208 /* ksched_yield: Yield the CPU.
210 int ksched_yield(register_t *ret, struct ksched *ksched)
216 int ksched_get_priority_max(register_t*ret, struct ksched *ksched, int policy)
238 int ksched_get_priority_min(register_t *ret, struct ksched *ksched, int policy)
260 int ksched_rr_get_interval(register_t *ret, struct ksched *ksched,
261 struct proc *p, struct timespec *timespec)
263 *timespec = ksched->rr_interval;